Hydrophobically coated/treated metal silicate abosrbent particles and personal care compositions thereof

ABSTRACT

Coated particles of metal (such as calcium) silicate that exhibit excellent odor neutralization and sebum absorption properties when present within certain cosmetic and/or personal care formulations and suspensions are provided. Uncoated calcium silicate exhibits a high pH level that may have a deleterious effect upon such cosmetic and/or personal care compositions, thereby rendering the overall composition ineffective for its intended purpose, particularly if the calcium silicate is present in its usual state at high loading levels. Alternatively, if certain materials present within personal care compositions exhibit a sufficiently low pH level, the effectiveness of such calcium silicates may be compromised as well. Such novel coated/treated calcium silicates thus permit high loadings of this beneficial odor neutralizing/sebum absorbing additive within cosmetic and/or personal care formulations without causing any appreciable instability issues or viscosity modification concerns or allow for coexistence with such low pH materials without any appreciable reduction in performance capabilities of the calcium silicates themselves. Certain personal care compositions comprising these novel coated calcium silicate particulates are encompassed within this invention as well.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of pending U.S. application Ser. No. 11/050,237,filed Feb. 3, 2005, the content of which is incorporated herein byreference in its entirety for all purposes.

FIELD OF THE INVENTION

This invention pertains to coated particles of metal (such as calcium)silicate that exhibit excellent odor neutralization and sebum absorptionproperties when present within certain cosmetic and/or personal careformulations and suspensions. Uncoated calcium silicate exhibits a highpH level that may have a deleterious effect upon such cosmetic and/orpersonal care compositions, thereby rendering the overall compositionineffective for its intended purpose, particularly if the calciumsilicate is present in its usual state at high loading levels.Alternatively, if certain materials present within personal carecompositions exhibit a sufficiently low pH level, the effectiveness ofsuch calcium silicates may be compromised as well. Such novelcoated/treated calcium silicates thus permit high loadings of thisbeneficial odor neutralizing/sebum absorbing additive within cosmeticand/or personal care formulations without causing any appreciableinstability issues or viscosity modification concerns or allow forcoexistence with such low pH materials without any appreciable reductionin performance capabilities of the calcium silicates themselves. Certainpersonal care compositions comprising these novel coated calciumsilicate particulates are encompassed within this invention as well.

BACKGROUND OF THE INVENTION

A broad array of topical personal care and personal hygiene products areavailable for application to human skin to counteract malodorsassociated with the human body, particularly those malodors resultingfrom and associated with perspiration. These products include sports andathletic sprays and powders, antiperspirants, foot and body powders,body sprays, and especially deodorants. Other types of products areavailable to absorb potentially destructive sebum oils and residuesgenerated by the sebaceous glands within a person's skin. The ability tocombat either of these undesirable results is quite favorable within thepersonal hygiene product industry and the search for new and effectiveadditives for such purposes has existed for many years.

As examples, malodors may be “masked” or concealed by placing asufficient amount of perfume composition in the deodorant in order tohide or cover the malodor. Perfumes provide the additional benefit ofimparting a desirable fragrance, such as a variety of different fresh,pastoral, or musk scents, to a cosmetic or personal care product.However, “masking” also has distinct limitations. Unfortunately, somemalodors cannot be masked simply by adding perfumes, because they arehighly volatile (and therefore diffuse quickly into the air) or becausethey are extremely potent. Indeed, in some cases it may be impossible toadd sufficient amounts of perfume in order to sufficiently conceal theunderlying malodor without also giving the personal care product anoverly strong, perfumed odor. Topical antimicrobials, such as triclosan,may also be applied to the skin since perspiration-associated bodymalodors are typically the result of interaction between microbes,perspiration and triglyceride secretions from the sebaceous glands,which combine to produce malodorous and pungent metabolites and/or fattyacids. Thus, by controlling the microbe population on the skin'ssurface, the malodor can be eliminated or reduced in intensity. However,the use of antimicrobial agents, particularly in excessive amounts, isstrongly discouraged because it may contribute to the developmentand/selection of microbes resistant to known antimicrobial compounds.Additionally, the build-up of antimicrobial agents in the human body issuspected of potentially producing heretofore unknown side effects.Furthermore, the general molecular structures of some antimicrobialshave been reported to cause skin irritation, obviously a result unwantedwithin skin treatment and personal hygiene formulations.

Another approach that avoids the aforementioned problems while alsoreducing malodor involves the use of odor absorbers, such as activatedcharcoal and zeolites. These odor absorbing compounds function byabsorbing odors and perspiration, and unlike the aforementionedtreatment compounds they do not irritate the skin or impart an overlyperfumed scent to the composition. However, charcoal and zeolite odorabsorbers have the disadvantage that as they get wet (e.g., they comeinto contact with perspiration) they can become ineffective at odorabsorption. For similar reasons, these odor absorbers can also bedifficult to formulate into compositions that contain even smallquantities of water.

It had been realized that metal silicate additives provide excellentmalodor protection as well as potential sebum absorption benefits withincosmetic, etc., compositions, such as within skin care and decorativecosmetics, as some examples. Unfortunately, it was also realized thatsuch silicate materials generally exist at high pH levels that createproblems for such formulations and compositions, particularly when theyare present in amounts that are necessary for the desired malodorneutralization and/or sebum absorption benefits to occur during use. Asa result, such materials may cause deleterious reactions and stabilityproblems within such cosmetic, personal hygiene, skin treatment, etc.,formulations and compositions (such as, as one example, renderingineffective certain pH sensitive antiperspirant salts). Furthermore,certain materials, in particular antiperspirant salts, may deleteriouslyaffect the performance of such malodor reducing compounds through ionicinteraction between the cation of the metal silicate and the anion ofthe antiperspirant salt. It has been noticed that certain amounts ofantiperspirant salts will gel, coagulate, or otherwise precipitate outof solution during storage when present simultaneously withuncoated/untreated metal (i.e., calcium) silicates. Although the amountof such antiperspirant salts is generally much higher than for themalodor-reducing calcium silicates, the overall effect has been found torender such calcium silicates less effective for their intended purposeand to reduce (although relatively slightly) the amount of the availablesalts for eventual precipitation on the target skin surface. There isthus a clear need to provide calcium silicate additives for such typesof personal care compositions that exhibit lower pH levels duringapplication of finished product forms in order to ensure the maximumeffectiveness of all the additives present within such formulations. Todate, no such improvement has been provided within the cosmeticformulation and/or personal hygiene product industries.

OBJECTS OF AND BRIEF SUMMARY OF THE INVENTION

It is therefore one object of this invention to provide metal, andpreferably, though not necessarily, calcium, silicate particles that,when in a dispersion form within a cosmetic and/or deodorantformulation, and present at a concentration suitable to permit malodorneutralization from a person's skin, exhibits a pH level sufficientlylow as not to destabilize or alter the functionality of otheringredients present within the target finished cosmetic and/or deodorantformulations.

Accordingly, the present invention encompasses particulate metal (again,preferably, though not necessarily, calcium) silicate materials that areat least partially coated with an organic film. Such a film shouldexhibit either a) an ability to erode when subjected to sufficient pHchanges or b) sufficient porosity to permit migration of metal ions orisovaleric acid there through. The invention also encompasses includes afluid or solid personal care product comprising such a coated/treatedmetal (i.e., calcium) silicate material and a vehicle. Additionally,this invention encompasses a deodorant formulation comprising such acoated/treated metal (i.e., calcium) silicate material and at least oneantiperspirant salt. The invention also includes a method of inhibitingbody odor by applying to the skin an effective amount of a personal carecomposition comprising such coated/treated metal silicate materials.

DETAILED DESCRIPTION OF THE INVENTION

All parts, percentages and ratios used herein are expressed by weightunless otherwise specified. All documents cited herein are incorporatedby reference.

By “personal care compositions” it is meant compositions that compriseat least one material (in addition to the inventive coated/treatedcalcium silicates) that is typically utilized for the treatment of aperson's skin (such as, as examples, skin softeners, antiperspirantsalts, cosmetics, and the like). Types of such personal carecompositions include, without limitation, either fluid or solid innature, deodorants, anti-perspirants, athletic sprays, body sprays, hairconditioners, shampoo, skin conditioners, body washes, liquid bathsoaps, facial cleansers, make-up removers, baby baths, hand soaps,make-up foundation, skin-coloring formulations, sunscreens, and thelike.

It has been determined that coating metal silicate materials (a termthat is intended to encompass a variety of different materials,including, without limitation, calcium silicate, calciumaluminosilicate, calcium zinc silicate, magnesium silicate, magnesiumzinc silicate, and calcium magnesium silicate; this term is furtherelaborated upon below) permits the inclusion of relatively high amountsof such materials within personal care compositions in order to provideeffective benefits associated with such materials as well as not impairthe effectiveness of the other components present within the sameformulations nor deleteriously affect the effectiveness of the metalsilicates when present with low pH (˜4.5 pH, for example) ionicmaterials. For purposes of this invention, the term “calcium silicate”shall indicate any metal silicate that includes at least calcium,magnesium, or zinc cation therein; thus, any compounds that includefurther metal cation species, such as aluminum, zinc, magnesium, etc.,are considered to be within this definition.

Additionally, particulate metal silicate materials frequently exhibitother problems during composition manufacture as well as during storageand use. For example, uncoated materials of such type have been known toprove difficult to properly disperse without created precipitates withinthe bottom of the fluid container and, as noted above, the high pHlevels of such uncoated materials can effectively destabilize theoverall composition or at least impair the effectiveness of some if notall of the individual active ingredients present therein.

Surprisingly, then, it was also determined that coating, even partially,such calcium silicate materials prior to inclusion within a personalcare composition actually aids in the incorporation of such materialstherein, more rapidly disperses to provide greater homogeneity withinthe target formulation, and does not exhibit any appreciable propensityto destabilize such lower pH compositions. Furthermore, even moresurprisingly, the presence of a coating on such calcium silicatematerials did not appreciably reduce the ability of such additives toabsorb malodors (particularly isovaleric acid) as compared with uncoatedcalcium silicate particulates. Even more importantly, it was discoveredthat the minimum level of coating needed for proper functioning in theserespects did not show any effects on the viscosity of the targetpersonal care formulations (if fluid in nature) either (as opposed toother coated materials that require certain types of film-formingcoatings and in sufficiently high amounts that, upon dissolution withinan aqueous- or nonaqueous-based composition the film-forming materialscan actually modify the viscosity to a level undesired). Lastly, thesurface characteristics of such particulate calcium silicate materialsmay also be modified through the utilization of such a beneficialcoating such that the feel of the overall personal care composition maybe altered in a favorable fashion as well.

The present invention includes topical personal care compositionscomprising a coated metal silicate along with at least one acceptablevehicle (such as diluents or carriers) for the odor-absorbing calciumsilicate, so as to facilitate the calcium silicate's distribution whenthe composition is applied to the skin. (Suitable vehicles, as well asother suitable personal care composition ingredients are discussed ingreater detail, below). The silicates act as odor absorbents andneutralizers to absorb and neutralize body malodors, particularly bodymalodors associated with perspiration. By incorporating these calciumsilicates, a wide variety of personal care compositions may be producedthat provide effective, long-lasting absorption and neutralization ofodors. This allows effective body malodor suppression without theoveruse of perfumes or antimicrobial agents. In addition to thesebenefits, the calcium silicate also improves the “feel” of personal carecompositions in which it is incorporated. Particularly, the personalcare compositions have a smoother feel when applied and in contact withthe skin.

That personal care compositions incorporating the inventivecoated/treated metal silicates are capable of providing effective odorneutralization and suppression would itself be surprising to a person ofordinary skill in the art. This is because the particulate calciumsilicates are coated with several other ingredients, and thus would seemincapable of neutralizing and suppressing body malodors. However, by thepresent invention, personal care compositions have been formulated thatfully incorporate coated/treated calcium silicate particles withoutdiminishing the ability of the calcium particles to absorb andneutralize odors.

As noted above, the coated/treated metal (i.e., calcium) silicates inthe cosmetic compositions prepared according to the present inventionabsorb both malodors originating from human skin as well as absorb thefatty acids found on the skin even while such compounds comprisebarriers to direct contact with the molecular surfaces to which malodorsand fatty acids readily react. Calcium silicates, as a preferred exampleof a preferred metal silicate, are believed to offer two measures toneutralize body malodors: they not only absorb the malodors themselves,but they also reduce the quantities of fatty acids that are part of thecause of the malodors. It is believed that such malodorous compounds areattracted into the intraparticle pores and interstices that are formedwithin the calcium silicates. The molar composition of the metalsilicate materials permits dissociation of the metal cation and thesilicate anion. Such freed metal cations (such as calcium, magnesiumzinc, etc.) can then react with the available anions (such as long-chainfatty acids, for instance isovaleric acid) of the targetedmalodor-creating compounds to create low-volatility salts. As a result,such newly formed salts exhibit reduced volatility into the surroundingenvironment, and, ultimately, the chances of smelling such non-volatizedcompounds are drastically reduced if not prevented.

The organic films (coatings) applied to the calcium silicates thussurprisingly provide protection for the other pH sensitive ingredientspresent within such personal care compositions while also exhibiting theability to permit such calcium silicates to absorb malodors and/or sebumfrom treated skin. While not wishing to be limited by theory, it isbelieved that the present organic films do in fact provide protectionfrom low pH materials by providing at least a partial barrier to anysuch contact with low pH components, whereas such films also exhibit thetendency to either erode over time while in solution (upon contact withwater or upon exposure to materials exhibiting significantly differentpH levels) or after application to a person's skin (upon exposure tochanges to pH levels, such as contact with acids present on skin, suchas isovaleric acid, or as contact with high pH perspiration) or toexhibit sufficient porosity to permit diffusion of calcium ions throughsuch a barrier film from the calcium silicate, or to permit the targetedacids to diffuse through the barrier film to the calcium silicate.Similar results exist for the other metal silicates included within thisclass of compounds intended for utilization within this invention.

These metal silicates are most typically prepared by the reaction of areactive silica with an alkaline earth metal reactant, preferably analkaline earth metal oxide or hydroxide, and a source of aluminum suchas sodium aluminate or alumina. Such materials can generally berepresented by the formula Ca_(x)M_(y)SiO_(z), wherein M is one of moremultivalent cations selected from Mg, Al, and Zn, preferably Mg, and xis the number of moles of the calcium cations and is between 0 and 4,preferably between 0.5 and 2, y is the number of moles of such othermetal cations and is between 0 and 4, z is the number of moles requiredto balance the overall charge of the metal cations, and x+y is from 0.5to 6, preferably from 1 to 4, most preferably from 1 to 2. Because thefinal properties of the silicate are dependent on the reactivity of thesilica, the silica source is preferred to be the reaction product of asoluble silicate, such as, but not limited to sodium silicate, and amineral acid, such as sulfuric acid. Suitable synthetic amorphousalkaline earth metal silicates are manufactured by the J.M. HuberCorporation and are sold in different grades under the trademarkHUBERDERM®. Methods and techniques for preparing these silicates arediscussed in greater detail in U.S. Pat. No. 4,557,916. Other suitableamorphous silicates are available from J.M. Huber Corporation such assodium aluminosilicate sold under the trademark ZEOLEX® and sodiummagnesium aluminosilicate sold under the trademark HYDREX®. HUBERDERM®1000, a calcium silicate, is also available from J.M. Huber Corporation.The odor absorption and neutralization properties of some of thesematerials are discussed in greater detail in the Examples, below.

Personal care compositions prepared according to the present inventioncomprise about 0.5 wt % to about 20 wt %, preferably about 1 wt % toabout 10 wt % of the odor neutralizing metal silicate. In addition tothe metal silicate, the present personal care compositions will alsocomprise one or more dermatologically acceptable cosmetic ingredients.

The coating materials to be applied may be selected from the group ofsuitable organic hydrophilic polymers for coating, include starch, gumarabic, gum karaya, gum tragacanth, guar gum, locust bean gum, xanthangum, carrageenan, alginate salt, casein, dextran, pectin, agar,sorbitol, 2-hyroxyethyl starch, 2-aminoethyl starch, maltodextrin,amylodextrin, 2-hydroxyethyl cellulose, methyl cellulose, carboxymethylcellulose salt, cellulose sulfate salt, chitosan, chitosan acetate,polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol,polyethylene oxide, polyvinyl alcohol/acetate, polyacrylamide, and thelike. Such hydrophilic polymers exhibit the proper degree of erodibilitywhen in solution or when applied to a persons' skin and subsequently (orsimultaneously) subjected to pH changes due to perspiration. Others inthis list exhibit sufficient porosity when applied to the metal silicatematerials to permit migration of metal ions therethrough or, preferably,the migration of isovaleric acid therethrough in order for the silicateto neutralize such an undesirable odor-producing compound. Polyvinylacetate is illustrative of a water-insoluble polymer which can beincluded as an additional coating component to moderate thehydrophilicity of a hydrophilic polymer coating. One skilled in the artwill appreciate other various hydrophilic polymers that are within thescope of the present invention.

Suitable water-insoluble (hydrophobic) organic materials, alone or incombination with one or more other components, for producing films forat least partially coating such absorbent particles include polyvinylacetate, polyacrylamide, polyvinyl chloride, polystyrene, polyethylene,polymethacrylate, paraffin wax, carnauba wax, beeswax, stearyl alcohol,zein, shellac, edible fat, C₈-C₂₄ fatty acids (for example butyric acid,palmitic acid, lauric acid, stearic acid, isostearic acid) and theiralkali metal salts (i.e. sodium stearate), and the like. As for thehydrophilic polymers listed above, these films exhibit the proper degreeof erosion upon exposure to sufficient shifts in pH, as well as certaindegrees of porosity for proper functioning of the metal silicatematerials even when coated.

Either type of film may be utilized, as well as combinations thereof inorder to provide the proper degree of erodibility while in solution orwhen applied to a target skin surface, or to exhibit the proper degreeof porosity for the diffusion of the desired acids or the diffusion ofthe calcium ions. As such, any degree of coating may be utilized.Complete coating would be preferable when the metal silicate materialsare subject to significantly low pH levels in solution and the filmmaterials permit effective porosity, as noted above, or erode at aproper rate in order to permit as efficient use of the benefitsavailable from such calcium silicate materials by the user. Partialcoating can thus be performed as well, particularly if the solution inwhich the metal silicate materials are present do not present as drastica pH shift, as well as wherein the organic films themselves exhibitlower degrees of porosity. Any level of selection of porosity, coating,etc., may thus be followed and would be well within the purview of theordinarily skilled artisan for such a purpose.

Such materials may be applied in any manner, such as, as non-limitingexamples, coating or encapsulation techniques, including fluid-bedcoating, spray drying or film coating, spray drying and spray chilling,microencapsulation, coacervation and phase-separation processes, fluidbed coating (such as, without limitation, Wurster air-suspensioncoating), interfacial polymerization processes, co-extrusionmicroencapsulation processes, and spinning disc coating. Preferably,spray drying or fluid-bed coating.

The degree of coating may be controlled through application of thedesired weight percentage of polymer or other additives using techniqueswell understood by those in the coating field. The minimum levelrequired for proper functioning will vary depending on the type ofcoating and the desired protective effect. Preferably, the coating levelwill be between 1% and 30%, more preferably between 0.5% and 15%. Acontinuous (completely coated)-erodible or selectively porous organicfilm (such as carboxymethylcellulose, as one non-limiting example) ispreferable for compositions of antiperspirant salts and these inventivematerials, again as one non-limiting example. The level of coating isnot altogether critical as much as the materials should be designed toachieve the goals of the ultimate formulator for the target personalcare composition. Thus, although these levels are suggestions, thecoating level itself should be sufficient ultimately to provideprotection from low pH ingredients, as well as protect pH sensitivecomponents therein, to provide a certain degree of timed release of thecalcium silicate materials themselves when in solution and when appliedto a user's skin, and/or to aid in flow, suspension, or sensoryproperties for the overall composition.

Dermatologically acceptable cosmetic ingredients include first and mostimportantly a diluent or carrier. The vehicle, diluent or carrier may beselected from a wide range of ingredients. The vehicle may comprisewater and/or a water-miscible or dispersible organic liquid or liquidsand alternatively or additionally a water-immiscible liquid or liquidsand waxes. The cosmetically acceptable vehicle will preferably form from80% to 99% by weight of the composition, and can, in the absence ofother cosmetic adjuncts, form the balance of the composition. Thevehicle may be aqueous, non-aqueous or a combination of both, such as anemulsion. In a combination vehicle, an oil or oily material may bepresent, together with one or more emulsifiers to provide either awater-in-oil emulsion or an oil-in-water emulsion, depending largely onthe average hydrophilic-lipophilic balance (HLB) of the emulsifiersemployed. This also includes multiple emulsions: water-in-oil-in-wateror oil-in-water-in-oil emulsions. For sebum absorption purposes, it isimportant that the inventive coated/treated calcium silicate not bepresent within the oil phase of any emulsion since such calciumsilicates would be exhausted in terms of absorbing the oil portion ofsuch a formulation prior to any chance of properly performing afterapplication to a person's skin.

In the case where the composition contains a combination of aqueous andnon-aqueous vehicle components, the aqueous phase can be from about 90wt. % to about 10 wt. % of the vehicle, as can the non-aqueous phase. Inan embodiment of the invention where the vehicle is aqueous or iscomprised of a mixture of aqueous and non-aqueous components, preferablythe vehicle is at least 80 wt % water, by weight of the vehicle.Preferably, water comprises at least 85 wt % of the inventivecomposition, and most preferably from 90 to 95 wt % of the composition.

In an embodiment of the invention where the vehicle is comprised ofnon-aqueous components, the dermatologically acceptable non-aqueouscosmetic ingredients in the vehicle will usually form from 80% to 99.9%by weight of the composition, and may, in the absence of other cosmeticadjuncts, form the balance of the composition.

Examples of suitable non-aqueous carriers may include alcohols,polyalkoxylated glycols (such as propylene glycol), volatile andnonvolatile liquid silicone carriers (such as cyclicsilicone polymers),hydrocarbon and mineral oils and branched chain hydrocarbons. Specific,non-limiting examples of organic liquids suitable for use includeoctyldodecanol, butyl stearate, diisopropyl maleate, and combinationsthereof. Also suitable for use are acrylic acid-based polymers.

It is desirable that the odor absorbing ingredient in the inventivecompositions remains substantially localized in the region of the bodyto which it has been topically applied. In order to assist this tohappen and also to enable alternative dispensers for the composition tobe employed, the vehicle may be thickened or structured, for example byintroducing one or more materials for that purpose. Thickened orstructured compositions commonly adopt the form of firm sticks, softsolids and creams. In such circumstances, the materials are oftenreferred to as structurants or gellants and may sometimes alternativelybe called thickeners, depending on the final form of the composition.The vehicle may be further diluted with a volatile propellant and usedas an aerosol; may be mixed with an additional liquid and/or otheringredients and used, for example, as a roll-on or squeeze-sprayproduct; or mixed with one or more thickeners and/or structurants andused, for example, as a gel, soft solid, or solid stick product.

Exemplary thickeners are cross-linked polyacrylate materials availableunder the trademark CARBOPOL® from the B.F. Goodrich Company. Gums maybe employed such as xanthan, carrageenan, gelatin, karaya, pectin andlocust beans gum. Under certain circumstances, the thickening functionmay be accomplished by a material also serving as a carrier or emollientvehicle. For instance, silicone gums in excess of 10 centistokes andesters such as glycerol stearate have such dual functionality. Athickener will usually be present in amounts anywhere from 0.1 to 20% byweight, preferably from about 0.5% to 10% by weight of the composition.

Other dermatologically acceptable cosmetic ingredients include rheologyaffecting agents such as solidifying agents and gellants. Thesolidifying agents act to provide solidity to a personal carecomposition so that they are in solid (or semi-solid) form at roomtemperature. Suitable solidifying agents include especially high meltingpoint waxes (melting points between 65° C.-110° C.) which includehydrogenated castor oil, paraffin, synthetic wax, ceresin, beeswax, andother such waxes. Also acceptable are low melting point waxes (meltingpoints between 37° C.-65° C.), which include fatty alcohols, fattyacids, fatty acids esters, fatty acid amides, and the like.

Gellants are used in the case of solid stick compositions, to give thestick an appropriate consistency and provide an appropriate gel matrixand product hardness at the completion of processing. The gelling agentswill vary depending on the particular form of the personal carecomposition and whether the personal care composition is aqueous ornonaqueous. Suitable gellants include esters and amides of fatty acid orhydroxy fatty acid gellants, fatty acid gellants, salts of fatty acids,esters and amides of fatty acid or hydroxy fatty acid gellants,cholesterolic materials, lanolinolic materials, fatty alcohols,triglycerides, substituted sorbitol acetal compounds, such as mono-and/or di-benzylidene sorbitols, such as, as one non-limiting example,3,4-dimethylbenzylidene sorbitol, and other suitable solid,non-polymeric gellants. Preferred gellants (for both aqueous andnonaqueous compositions) include fatty alcohols, most preferably stearylalcohol. Amounts of these gellant components may range anywhere from0.001% up to 20% by weight of the composition.

The inventive compositions may contain any of a number of desired“active” ingredients, including drug substances such asanti-inflammatory agents, topical anesthetics, antimycotics, etc.; skinprotectants or conditioners; humectants; and the like, depending on theintended uses for the formulations.

Antiperspirant salts possible as materials within the inventive personalcare compositions include, without limitation, any aluminum astringentantiperspirant salt or aluminum and/or zirconium astringent complex canbe employed herein. Salts useful as astringent antiperspirant salts oras components of astringent complexes include aluminum halides, aluminumhydroxy-halides, zirconyl oxyhalides, zirconyl hydroxy-halides, andmixtures of these materials.

Aluminum salts of this type include aluminum chloride and the aluminumhydroxyhalides having the general formula Al₂(OH)_(x)Q_(y)XH₂O where Qis chlorine, bromine or iodine; where x is from about 2 to about 5, andx+y=about 6, and x and y do not need to be integers; and where X is fromabout 1 to about 6. Aluminum salts of this type can be prepared in themanner described more fully in U.S. Pat. No. 3,887,692 issued to Gilmanon Jun. 3, 1975, and U.S. Pat. No. 3,904,741 issued to Jones and Rubinoon Sep. 9, 1975.

The zirconium compounds which are useful in the present inventioninclude both the zirconium oxy salts and zirconium hydroxy salts, alsoreferred to as the zirconyl salts and zirconyl hydroxy salts. Thesecompounds may be represented by the following general empirical formula:ZrO(OH)₂-n_(z)B_(z)wherein z may vary from about 0.9 to about 2 and need not be an integer,n is the valence of B, 2-nz is greater than or equal to 0, and B may beselected from the group consisting of halides, nitrate, sulfamate,sulfate, and mixtures thereof. Although only zirconium compounds areexemplified in this specification, it will be understood that otherGroup IVB metal compounds, including hafnium, can be used in the presentinvention.

As with the basic aluminum compounds, it will be understood that theabove formula is greatly simplified and is intended to represent andinclude compounds having coordinated and/or bound water in variousquantities, as well as polymers, mixtures and complexes of the above. Aswill be seen from the above formula, the zirconium hydroxy saltsactually represent a range of compounds having various amounts of thehydroxy group, varying from about 1.1 to only slightly greater than zerogroups per molecule.

As alluded to above, one of the more significant problems faced byutilizing calcium silicate within certain personal care compositions isthe tendency of such compounds to interact with the cations and anionsof low pH salts. In particular, it has been realized that antiperspirantsalts exhibit both of these properties to the extent that compatibilityand stability of both materials may be compromised during storage of adeodorant composition comprising both types of materials and exhibitinga resultant and sufficiently low pH (believed to be as high as 4.5 pH)to generate such deleterious ionic interactions. Since the inclusion ofa malodor reducing compound within such a type of composition isbeneficial, there is thus an evident need to facilitate coexistence ofsuch materials without any appreciable loss of performance of either.

Without a coating, calcium silicates appear to react readily with thecationic species of such low pH antiperspirant salts (generally eitheraluminum or zirconium ions), thus eliminating the benefits accorded theuser through destruction of the needed molecular structure of thecalcium silicate itself. Likewise, however, the reaction of the calciumcation with the anion of the antiperspirant salt may cause precipitationof the salt out of solution prior to contact with a user's skin. Suchsalts generally function by remaining in solution until reacting with asufficiently alkaline source (preferably, the perspiration on a person'sskin), at which time the result is a precipitate that migrates to sweatducts on the skin surface and “plugs” such cavities to prevent or slowthe rate of perspiration. The high alkalinity of calcium silicates issufficient to cause at least some premature precipitation, therebyrendering at least some of the salts ineffective. Such a two-wayreduction in effectiveness is thus to be avoided in order to permitutilization of the full benefit of the malodor reducer and theperspiration reducer simultaneously. The inventive coated/treatedcalcium silicates have been found to provide such desired results aswell as other benefits.

The fluid or solid personal care products prepared according to thepresent invention may also include other optional components. The CTFACosmetic Ingredient Handbook, Tenth Edition, 2004, which is incorporatedby reference herein in its entirety, describes a wide variety ofcosmetic and pharmaceutical ingredients commonly used in skin carecompositions, and which are suitable for use in the compositions of thepresent invention. These optional components include pH bufferingagents, additional malodor control agents, fragrance materials, dyes,and pigments, preservatives, skin aids (e.g., aloe), cosmeticastringents, liquid or solid emollients, emulsifiers, film formers,propellants, skin-conditioning agents, such as humectants, skinprotectants, solvents, solubilizing agents, suspending agents,surfactants, waterproofing agents, viscosity increasing agents (aqueousand nonaqueous), waxes, wetting agents, and other optional components.Amounts of these adjunct components may range anywhere form 0.001% up to20% by weight of the composition.

The products themselves may be formulated to be in a variety of forms,such as solid and semi-solid stick deodorants (such as emulsion sticksor suspensoid sticks), roll-on deodorants, and deodorant aerosol andpump-sprays, and even soap bars.

The personal care compositions of the present invention may be preparedby any known or otherwise effective technique suitable for providing afluid personal care composition having the essential materials describedherein. Techniques for forming such compositions are very well known inthe art. The present invention is not dependent upon any particularformulation technique, it being recognized that the choice of specificformulation components may well make necessary some specific formulationprocedure.

Methods for preparing the personal care compositions of the presentinvention include conventional formulation and mixing techniques. Manyvariations of formulating the compositions of the present inventionexist, and all are considered within the scope of the present invention.Suitable methods include combining the calcium silicate odorabsorbing/neutralizing agent with part or all of the liquid vehicle. Aliquid may be entirely absorbed into the calcium silicate, and if so,additional liquid or liquids and other materials are added until thecalcium silicate is evenly dispersed. A thickener or gellant is addedand the composition is mixed and may be heated, if required forhomogenous incorporation. Adjunct and/or additional materials may beadded at this point, and the batch may be allowed to cool, if necessary.The thickened or gelled composition is allowed to viscosity or solidifyin a suitable container or dispenser.

Preferred Embodiments of the Inventions

Test Protocols

Where mentioned in this application, the surface area was determined bythe BET nitrogen absorption method of Brunaur et al., as reported in theJ. Am. Chem. Soc. 60, 309 (1938).

Organic coating treatment level is calculated from the amounts ofingredients used in the example preparation and is expressed as a weightto weight percentage.

Median particle size (MPS) was determined using a Model LA-910 laserlight scattering instrument available from Horiba Instruments, Boothwyn,Pa. A laser beam is projected through a transparent cell, which containsa stream of moving particles suspended in a liquid. Light rays, whichstrike the particles, are scattered through angles which are inverselyproportional to their sizes. The photodetector array measures thequantity of light at several predetermined angles. Electrical signalsproportional to the measured light flux values are then processed by amicrocomputer system to form a multi-channel histogram of the particlesize distribution.

Oil absorption, using linseed oil, was determined by the rubout method.This method is based on a principle of mixing oil with a silicate byrubbing with a spatula on a smooth surface until a stiff putty-likepaste is formed. By measuring the quantity of oil required to have apaste mixture, which will curl when spread out, one can calculate theoil absorption value of the silicate—the value which represents thevolume of oil required per unit weight of silicate to saturate thesilicate sorptive capacity. Calculation of the oil absorption value wasdone as follows: $\begin{matrix}{{{Oil}\quad{absorption}} = {\frac{{ml}\quad{oil}\quad{absorbed}}{{{weight}\quad{of}\quad{silicate}},{grams}} \times 100}} \\{= {{ml}\quad{{oil}/100}\quad{gram}\quad{silicate}}}\end{matrix}$

Isovaleric acid is associated with and contributes to foot and bodyperspirative malodors. Commercial samples of this malodorous materialwas used as a model compound to assess the ability of cosmeticcompositions prepared according to the present invention, comprisingsynthetic metal silicate materials to remove the odors associated withthese malodorous materials.

Samples for in vitro odor capacity analysis were prepared as follows.Test specimens were prepared by weighing 0.25 grams of an odorabsorbing/neutralizing test compound into a 20-ml crimp cap headspacesampling vial (VWR part no. 66064-348). Then 5 ml of 5% NaCl solutionand an appropriate volume of isovaleric acid (Sigma-Aldrich part no.3314699) were added to the vial. The volume of isovaleric acid waschosen such that the residual acid not neutralized will be within thelinear working range, i.e. 20-100 μl (establishment of the linearworking range is described below). This volume is determined fromhistorical data, physical properties of the test substance and trial anderror. The resulting mixture was then capped, vigorously agitated on avortex agitator, shaken by hand, allowed to equilibrate for 24 hours andthen analyzed using GCMS (“Gas Chromatography Mass Spectrometry”).

A Hewlett Packard 5890 Gas Chromatograph with a HP5972 Mass SelectorDetector was utilized for this analysis (GCMS analysis).

The sampling method used to determine the detectable quantity ofnon-absorbed odor causing substance (isovaleric acid) or odorneutralization capacity of each specimen was Solid Phase Microextraction(SPME) headspace analysis.

Each sample vial was sampled using a 100 μm PDMS Solid PhaseMicroextraction fiber, available from Supelco/Sigma-Aldrich, part no.57300-U and a manual fiber holder, part no. 57330-U. The fiber wasexposed to the vial headspace for 5 minutes at room temperature thendesorbed into the GCMS (as noted above). The GC was outfitted with aRestek Stabilwax column (60 m length, 0.25 mm id., 0.25 μm df) availablefrom Restek Corporation, Bellfonte, Pa. as part no. 10626. The GCMSsystem was set to the following operating conditions. Low TemperatureOdor Capacity GCMS Operating Conditions For the GCMS: Temp. profile: 4min @ 50° C. Ramp 10° C./min to 200° C. Ramp 20° C./min to 240° C.Carrier gas: He, 24 psi Injector: 250° C. Split - 100 ml/min. 1 mmstraight liner Detector: 280° C. MS scan mode 35-550 AMU

A linear working range was established as follows. To prepare standards,vials were prepared containing 5 ml of 5% NaCl and 20, 40, 60, 80, and100 μL of isovaleric acid. The vials of standards were then analyzed asdescribed above and the peak area plotted against the isovaleric acidaddition. Typically, a linear correlation of R²=0.98 to 0.99 can beachieved.

To compensate for day to day drift in detector response, calibration wasaccomplished by running replicate standards at a 60 μl loading in 5 mls5% NaCl at the beginning and end of each analytical set. The averagepeak area of these runs is used to calculate a single point responsefactor at 60 μls.

To calculate the odor neutralizing capacity of each specimen, a knownamount of isovaleric acid was added to the 0.25 g specimen in 5 mls 5%NaCl. The amount added was such that the excess of isovaleric acid inthe vial available for SPME analysis—i.e. not neutralized, falls closeto the midpoint of the linear working range. The residual amount of acidin the vial, calculated from the 60 μl response factor was subtractedfrom the amount added, and divided by the specimen weight. This is theamount of isovaleric acid neutralized or the odor absorbing capacity inμl/g.${{µl}\quad{Residual}\quad{Isovaleric}\quad{Acid}} = \frac{{Peak}\quad{Area}\quad{Specimen} \times 60\quad{µl}}{{Average}\quad{Peak}\quad{Area}{\quad\quad}60\quad{µl}\quad{Replicates}}$${{µl}\text{/}g\quad{Isovaleric}\quad{Acid}\quad{Neutralized}} = \frac{{{Isovaleric}\quad{Acid}\quad{Added}} - {{Residual}\quad{Isovaleric}\quad{Acid}}}{{{Specimen}\quad{Weight}},g}$Coated Particulate Production

EXAMPLES 1-2

In these examples, calcium silicates were produced in-situ with anorganic polymer coating. In a first step of these examples, amorphoussilica suitable for use in the production of the inventive calciumsilicates was prepared by adding sulfuric acid to a dilute waterglasssolution in a well-agitated mixing vessel to affect the precipitation ofamorphous hydrated silica. Specifically, a total of 1052 liters ofsulfuric acid at a concentration of 11.4% was added at a rate of 17.8lpm to 1893 liters of waterglass solution (3.3 SiO₂/Na₂O mole ratio)containing 13% sodium silicate solids while mixing at a temperature of83° C. The addition of the sulfuric acid was continued until a pH of 5.5was obtained, and the reaction mixture was digested for 1 hr. Theresulting suspension of silica particles was recovered by filtration,and washed and dried to form a finely divided reactive silica powder. Itis equally useful to retain the undried material in the form of afiltered cake, as an intermediate material for subsequent synthesis.

The reactive silica produced above was then slurried in water to 14.56%solids content and 616 g of this silica slurry was added to a reactionvessel equipped with a constant torque agitator and paddle blades and aspecified amount of a polymer and water were added to the reactor. Themixture was brought to 70° C. and digested for 5 minutes. Then 292 g oflime slurry at 16.2% solids were added to the reactor. The reactortemperature was raised to 95° C. and the reaction mixture digested for 1hour. The resulting coated calcium silicate (CaSiO₃) was then filteredand dried overnight at 150° C., then milled in a coffee mill.

The amount of water and specific polymer for Example 1 and 2 are givenin Table 1 below. TABLE 1 Example 1 Example 2 Water, g 1270.7 1270.7 1%CEKOL ® 2000 CMC, g 136.9 0 1.17% CHITOLINK ® 501, g 0 117

Several properties of Example 1 and 2 products, as well as theproperties of a control sample that was made by the same procedurewithout any polymer addition were determined according to the methodsdescribed above and are summarized in Table 2 below. TABLE 2 Example No.1 2 Control Organic Treatment CEKOL ® CHITOLINK ® None 2000 501 %Treatment 1 1 0 Odor Neutralization (μl/g) 917 817 918 5% pH 9.45 9.4310 BET, M²/g 115 95 — MPS, μm 10.2 11.3 —

CEKOL® 2000 is sodium carboxymethyl cellulose available from Noviant B.V., Nijmegen, the Netherlands and CHITOLINK® 501 is 1% chitosan acetateavailable from Marine Extract, Ltd, Shippagan, New Brunswick, Calif.

It is seen in Table 2 above that the odor neutralization capacity ofExample 1 and Example 2 is comparable to the control sample (notreatment), however the pH was reduced significantly.

EXAMPLES 3-5

In these examples, already formed calcium silicate was post-treated withdifferent treatment amounts of various sodium carboxymethyl cellulosepolymers to reduce the product pH. HUBERDERM® 1000 calcium silicate(CaSiO₃) available from J.M. Huber Corporation, Havre de Grace, Md., wasadded to water to form a slurry in an agitated vessel using a constanttorque agitator fitted with paddle blades. To this slurry, a CMCsolution was added with additional water. The resultant mixture washeated to 95° C. and digested for 60 minutes. Finally, the resultantproduct was recovered by filtration, washed with 2 liters hot water, andthen dried overnight at 50° C. The process variables for Examples 3 to 5are summarized in Table 3. TABLE 3 Process Parameters Example 3 4 5Organic Treatment CEKOL ® CEKOL ® CEKOL ® 500T 700 2000 % Treatment 5 55 Calcium Silicate, g 100 100 100 Water, g 900 900 900 CMC solution, g167 250 500 CMC concentration, % 3 2 1 Water added, g 150 0 0

CEKOL® 500T, 700 and 2000 carboxymethylcellulose (CMC) products areavailable from Noviant B. V., Nijmegen, the Netherlands. Examples 3-5and an untreated HUBERDERM® 1000 calcium silicate control were testedaccording to the methods described above. The analysis results aresummarized in Table 4 below. As above, the pH of the treated materialswas reduced significantly when compared to the control. TABLE 4 Example3 Example 4 Example 5 Control Treatment 5% 5% 5% none CEKOL ® CEKOL ®CEKOL ® 500T 700 2000 Odor Neutralization, 961 992 975 918 (μl/g) 5% pH9.1 9.1 9.35 10 BET, M²/g 76 — 133 — MPS. μm 4.8 — 9.1 —

EXAMPLE 6

In this example, calcium silicate was post-treated with cross-linkedchitosan to reduce the product pH. Into a vessel equipped with a highshear mixer (Silverson model L4R available from Silverson Machines,Ltd., Waterside, Chesham, Bucks, UK) was added 23.7 g HUBERDERM® 1000calcium silicate (CaSiO₃), 60 g water and 100 g of a mixture of 5% NaOHin methanol. The Silverson mixer was turn on and the mixture was stirredat 6000 rpm. While mixing, 90 g of a solution prepared by dissolving 2.5g chitosan (available from ICN Biomedical, Inc., Aurora, Ohio) and 2.5 gglycine in 100 g of aqueous 2% acetic acid was added to this slurry. Themixture was digested for 10 minutes with stirring continued. Theresultant product was filtered, reslurried in hot water, thenre-filtered and washed with cold water and dried overnight at 50° C. Thedried product was milled then reslurried in 200 g hot water and 100 mlof 25% glutaraldehyde and digested for 10 minutes at 50° C. The productwas recovered by filtration, washed with hot water, slurried in waterand re-filtered and washed with cold water and dried at 50° C.overnight.

The resultant product containing 5% cross-linked chitosan was analyzedaccording to the methods described above and had a pH of 9.2 and an odorneutralization capacity of 970 μl/g.

EXAMPLE 7-8

In these examples, already formed calcium silicate was post-treated withdifferent treatment amounts of various soluble polymers and tested forease of dispersion into aqueous and non-aqueous cosmetic systems. Thecalcium silicate was a 2.0 mole ratio Ca₂:SiO₄ product produced byadding a total of 1052 liters of sulfuric acid at a concentration of11.5% at a rate of 17.8 lpm (liters per minute) to 1893 liters ofwaterglass solution (3.3 SiO₂/Na₂O mole ratio) containing 13% sodiumsilicate solids while mixing at a temperature of 95° C. The addition ofthe sulfuric acid was continued until a pH of 5.5 was obtained, and thereaction mixture was digested for 1 hr. The resulting suspension ofsilica particles was recovered by filtration, and washed and dried toform a finely divided reactive silica powder.

95.3 kg reactive silica produced above was then slurried in water to17.7% solids in a reaction vessel equipped with a constant torqueagitator and paddle blades. Then 512 kg water and 233.8 kg lime slurryat 18.7% solids were added to the reactor. The reactor temperature wasraised to 95° C. and the reaction mixture digested for 60 minutes. Theresulting calcium silicate was then filtered, dried and milled.

A portion of the 2.0 mole ratio Ca₂:SiO₄ prepared above was retained asa control. Another portion was treated with CMC by adding 100 g calciumsilicate to 900 g water in an agitated vessel using a constant torqueagitator and paddle blades. To this slurry was added 167.3 g of 3%CEKOL® 500T CMC and 200 g water. The mixture was heated to 95° C. anddigested for 60 minutes, before being recovered, by filtration, thenwashed, and dried. This 2 mole ratio calcium silicate treated with 5%CMC was EXAMPLE 7.

Another portion of the 2 mole ratio calcium silicate prepared above wastreated with isostearic acid by mixing 100 g of calcium silicate with 10g liquid isostearic acid until homogenous. This 2 mole ratio calciumsilicate treated with 10% isostearic acid was EXAMPLE 8.

The untreated control calcium silicate was compared to inventive Example7 and 8 in different cosmetic systems by gently mixing (with a Teflonstir bar) 1 g calcium silicate into 50 g of a cosmetic system, whereinthe aqueous system tested was Dow Corning 1202, volatile silicone fluidand the non-aqueous system tested was light mineral oil. The time wasrecorded for the pigment to be completely and uniformly dispersed withresults summarized in Table 5. TABLE 5 Time to Sample Treatment SystemDispersion, min Control None Silicone Fluid >10 Example 7 5% CMCSilicone Fluid 7.2 Control None Mineral Oil 5 Example 8 10% IsostearicMineral Oil 3.5 acid

The above data shows that the inventive treated calcium silicates ofExamples 7 and 8 were dispersed into both aqueous and non-aqueoussystems more quickly than the control untreated calcium silicate. Infact, the untreated calcium silicate did not disperse uniformly into thesilicone fluid in even 10 minutes.

EXAMPLE 9

In this example, the odor neutralization capacity of sodium stearate andsodium stearate containing calcium silicate were compared. The Example 9sodium stearate/calcium silicate product was prepared by mixing 90 g ofsodium stearate with 10 g of calcium silicate (Ca₂SiO₄ prepared as aprecursor in Example 7-8).

Samples of Example 9 and the sodium stearate control were analyzed usingthe low temperature GCMS protocol described above. Isovaleric acid (50μl & 100 μl) was added separately to two dry powder specimens of each ofthe control and Example 9. The vials were capped, agitated using avortex mixer to distribute the acid, and then allowed to equilibrate for2 hrs at room temperature prior to sampling. The vials were then sampledfor 5 minutes at room temperature using a 100 μm PDMS SPME fiber anddesorbed into the GCMS under the conditions described above. Since thisexample is a head to head comparison, only the raw GCMS peak areas forisovaleric acid were compared. The results are summarized below in Table6. TABLE 6 Isovaleric Acid Sample ID added, μls GC Peak Area SodiumStearate control 50 18,333,024 Example 9 50 308,153 Sodium Stearatecontrol 100 19,162,081 Example 9 100 2,595,075

It is seen from the data in Table 6 that Example 9 showed verysignificant reduction of isovaleric acid detection as compared to thesodium stearate control samples.

EXAMPLE 10-11

In these examples, calcium silicate (Ca₂SiO₄ prepared as a precursor inExample 7-8) materials were coated with CMC, starch, or left uncoated.

For Example 10, the calcium silicate was coated in a Glatt fluid bedcoater (model GPCG-1 available from Air Techniques, Ramsey, N.J.) with asolution of CEKOL® 300 carboxymethylcellulose (CMC) available fromNoviant B. V., Nijmegen, the Netherlands. Example 10 product has amedian particle size of 5.8 μm, an oil absorption of 165 ml/100 g, a 5%pH of 9.79 and a BET surface area of 70 M²/g.

For Example 11, the calcium silicate was coated in the Glatt fluid bedcoater with a solution of Starch 1500 available from Colorcon, WestPoint, Pa. Example 11 product had a median particle size of 8.7 μm, anoil absorption of 166 ml/100 g, a 5% pH of 9.63 and a BET surface areaof 80 M²/g. Coating parameters for Example 10 and 11 are summarizedbelow in Table 7.

For Control A, the same calcium silicate used for Example 10 and 11 wasnot coated. TABLE 7 Coating Air Inlet Rate Velocity Temp. ExampleCoating % Coating ml/min Setting ° C. 10 CEKOL ® 300 5 10-12 5 67 11Starch 1500 5  8-14 4 75 Control A None Na Na Na Na

Example 10, Example 11, and the uncoated Control A were separatelysuspended in a 10% aqueous solution of aluminum chlorohydrate (ACH)available from Reheis, Inc., Berkeley Heights, N.J., stirred for 30minutes, recovered by filtration, washed, and dried for 16 hr at 105° C.The samples were evaluated using GCMS to determine their ability toabsorb isovaleric acid according to the low temperature GCMS methoddescribed previously. For comparison, a sample of uncoated calciumsilicate that was not exposed to aluminum chlorohydrate (Control B) wasalso measured. Results of the evaluation are summarized in Table 8below. TABLE 8 Portion Of Performance Retained Isovaleric Following ACHExample acid μl/g Exposure, % Example 10 1006 57.2 Example 11 1128 64.1Control A 450 25.6 Control B 1760 —

Untreated calcium silicate Control A lost about 75% of its capacity toabsorb isovaleric acid after exposure to a 10% aqueous solution ofaluminum chlorohydrate. Application of 5% w/w of coatings of the presentinvention allowed over 60% of the capacity to be retained.

EXAMPLE 12

In this example, calcium silicate (Ca₂SiO₄ prepared as a precursor inExample 7-8) was coated with polyethylene glycol (Example 12) or leftuncoated (Control). Specifically, 30 g calcium silicate was dispersed indeionized water and mixed at 10,000 rpm to a homogenous suspension usinga Silverson homogenizer model L4RT-A, available from Silverson Machines,Inc., East Longmeadow, Mass. In a separate container, 10 g PEG(polyethylene glycol) and 5 g PPG 14 propylene glycol butyl ether(Americol B.V., the Netherlands) along with 1 g TWEEN® 20(polyoxyethylenesorbitan monolaurate) available from ICI Americas, Inc.,Wilmington, Del., was added to 300 g isopropyl alcohol (IPA). The IPAsolution was added dropwise to the water suspension containing thecalcium silicate particles while continuing to mix at 10,000 rpm. Thefinal suspension was then added to a LABCONCO rotary vacuum evaporatorand the vacuum vessel immersed in a water bath heated to 60° C. toremove the IPA. The temperature was increased to 80° C. and evaporationwas continued until the dry coated particles could be removed as a freeflowing powder.

The coated particles were tested for absorption capacity according tothe methods described above and are summarized in Table 9 below. TABLE 9Isovaleric Acid % Organic Isovaleric Acid Capacity, μl/g ExampleTreatment Capacity, μl/g Calcium silicate 12 30 1209 1727 Control 0 17671767

On an active pigment basis there was no loss in performance by applyingthe coating.

These samples were next dispersed at a level of 1% wt/wt in a 10%solution of an antiperspirant salt, aluminum/zirconiumtetrachlorohydrex-Gly Summit AZG370 available from Summit Research Labs,Huguenot, N.Y. The dispersions were held at 25° C. until an interactionbetween the antiperspirant salt solution and silicate odor absorbentparticles was observed. An interaction manifests itself as a visualthickening or gelling of the antiperspirant salt solution; the resultsevinced the inferiority of the control. TABLE 10 % Organic ExampleTreatment Days stability 12 30 >20 Control 0 <7

EXAMPLES 13-15

In these examples, already formed calcium silicate was post-treated withdifferent treatment amounts of CEKOL® 500T CMC and tested odorabsorption properties. The calcium silicate was a 3.0 mole ratio Ca₃SiO₅product produced by adding a total of 1052 liters of sulfuric acid at aconcentration of 11.5% at a rate of 17.8 lpm (liters per minute) to 1893liters of waterglass solution (3.3 SiO₂/Na₂O mole ratio) containing 13%sodium silicate solids while mixing at a temperature of 95° C. Theaddition of the sulfuric acid was continued until a pH of 5.5 wasobtained, and the reaction mixture was digested for 1 hr. The resultingsuspension of silica particles was recovered by filtration, and driedovernight at 105° C. to form a finely divided reactive silica powder.

Next, 923.2 g reactive silica produced above was slurried in water to14.56% solids in a reaction vessel equipped with a constant torqueagitator and paddle blades. Then 200 g water and 3094.5 g lime slurry at15.0% solids were added to the reactor along with 200 g rinse water usedto rinse the lime slurry from its container. The reactor temperature wasraised to 95° C. and the reaction mixture was digested for 60 minutes.The resulting calcium silicate was then filtered, dried and milled.

A portion of the 3.0 mole ratio Ca₃:SiO₅ prepared above was retained asa control. Another portion of the 3 mole ratio calcium silicate preparedabove was treated with CMC by adding 100 g of the prepared calciumsilicate to 900 g water in an agitated vessel using a constant torqueagitator and paddle blades. To this slurry was added 33.4 g of 3% CEKOL®500T CMC and 200 g water. The mixture was heated to 95° C. and digestedfor 60 minutes, before being recovered by filtration, then washed, anddried. This 3 mole ratio calcium silicate treated with 1% CMC wasdesignated Example 13.

Another portion of Ca₃SiO₅ prepared above was treated with a differentamount of CMC by adding 100 g calcium silicate to 900 g water in anagitated vessel using a constant torque agitator and paddle blades. Tothis slurry was added 167.0 g of 3% CEKOL® 500T CMC and 400 g water. Themixture was heated to 95° C. and digested for 60 minutes, before beingrecovered by filtration, then washed, and dried. This 3 mole ratiocalcium silicate treated with 5% CMC was designated Example 14.

Another portion of the 3 mole ratio calcium silicate prepared above wastreated with a different amount of CMC by adding 100 g calcium silicateto 900 g water in an agitated vessel using a constant torque agitatorand paddle blades. To this slurry was added 334 g of 3% CEKOL® 500T CMCand 400 g water. The mixture was heated to 95° C. and digested for 60minutes, before being recovered by filtration, then washed, and dried.This 3 mole ratio calcium silicate treated with 10% CMC was designatedExample 15.

Examples 13-15 and an untreated 3 mole ratio calcium silicate controlwere tested for several properties according to the methods describedabove. The results are summarized in Table 11 below. TABLE 11 SampleExample Example Example Control 13 14 15 Treatment None 1% CMC 5% CMC10% CMC 5% pH 11.76 11.8 11.77 11.8 Odor Neutralization, μl/g) 2086 17951770 1700 BET, M²/g — 42 54 58 MPS, μm — 7.1 7.2 7.6

It is seen from the data above that all treatment levels providedimproved odor neutralization as compared to the uncoated control calciumsilicate.

EXAMPLE 16

In this example, magnesium silicate (Mg₂SiO₄) was prepared and treatedwith different organic films and then tested for odor neutralization.Reactive silica was made first by adding a total of 1052 liters ofsulfuric acid at a concentration of 11.5% at a rate of 17.8 lpm (litersper minute) to 1893 liters of waterglass solution (3.3 SiO₂/Na₂O moleratio) containing 13% sodium silicate solids while mixing at atemperature of 95° C. The addition of the sulfuric acid was continueduntil a pH of 5.5 was obtained, and the reaction mixture was digestedfor 1 hr. The resulting suspension of silica particles was recovered byfiltration, and dried overnight at 105° C. to form a finely dividedreactive silica powder.

The reactive silica produced above was slurried in water to 14.56%solids. Then 200 g water and 461.5 g of the silica slurry (14.56%solids) were mixed in a reaction vessel equipped with a constant torqueagitator and paddle blades. To this mixture was added 220.78 g magnesiumhydroxide slurry at 51% solids along with 300 g rinse water used torinse the Mg(OH)₂ slurry from the beaker. The reactor temperature wasraised to 90° C. and the reaction mixture digested for 60 minutes. Theresulting (2:1 mole ratio) magnesium silicate was then filtered and thefilter cake (wet cake) was retained for further coating. A portion ofthe wet cake was dried overnight at 150° C., milled to 7.7 μm anddesignated as Example 16 control. Example 16 Control has an oilabsorption of 76 ml/100 g and a BET surface area of 43 M²/g,

The formed magnesium silicate was next coated with various organic filmsand evaluated for odor neutralization. The coating was prepared bycombining 128 g of the magnesium silicate wet cake (38.9% solids)prepared above, 420 g water and 250 g of a 1% CEKOL® 2000 CMC solution.The mixture was heated to 95° C. and digested for 1 hour. The CMC coatedmagnesium silicate was recovered by filtration and dried overnight at105° C. and is designated as Example 16A.

The formed magnesium silicate was next coated with isostearic acid bycombining 46.27 g of the magnesium silicate wet cake (38.9% solids)prepared above and 2.0 g isostearic acid and mixing until the mixturebegan a homogenous fluid. The mixture was then dried overnight at 105°C. and the dried isostearic acid coated magnesium silicate is designatedas Example 16B. Several properties of Example 16 Control, Example 16Aand Example 16B were measured according to the methods described aboveand are summarized below in Table 12. TABLE 12 Sample Example 16 ExampleExample Control 16A 16B Treatment None 5% CMC 10% Isostearic Acid 5% pH8.80 9.47 9.13 Odor Neutralization, μl/g) 1925 1428 1075

EXAMPLE 17

In this example, calcium magnesium silicate (Ca_(0.5)Mg_(1.5)SiO₄) wasprepared by first forming reactive silica as described in Example 16.The reactive silica was slurried in water to 14.56% solids and 461.6 gof this slurry and 200 g water were mixed together and then 165.6 gmagnesium hydroxide slurry (51% solids) was added. The mixture wasdigested for 5 minutes and then 258.4 g lime slurry (16.19% solids) and200 g water used to rinse the beaker containing the lime slurry wasadded. The mixture was heated to 90° C. and digested for 1 hour. Theresulting calcium magnesium silicate was then filtered and the filtercake (wet cake) was retained for further coating. A portion of the wetcake was dried overnight at 150° C., milled and designated as Example 17Control. Example 17 Control has an oil absorption of 120 ml/100 g and aBET surface area of 124 M²/g.

The formed calcium magnesium silicate was next coated with variousorganic films and evaluated for odor neutralization. The coating wasprepared by combining 253.8 g of the calcium magnesium silicate wet cake(19.7% solids) prepared above, 296.1 g water and 250 g of a 1% CEKOL®2000 CMC solution. The mixture was heated to 95° C. and digested for 1hour. The CMC coated calcium magnesium silicate was recovered byfiltration and dried overnight at 105° C. and is designated as Example17A.

The formed calcium magnesium silicate was next coated with isostearicacid by combining 91.4 g of the calcium magnesium silicate wet cake(19.7% solids) prepared above and 2.0 g isostearic acid and mixing untilthe mixture began a homogenous fluid. The mixture was then driedovernight at 105° C. and the dried isostearic acid coated calciummagnesium silicate is designated as Example 17B. Several properties ofExample 17 Control, Example 17A and Example 17B were measured accordingto the methods described above and are summarized below in Table 13.TABLE 13 Sample Example 17 Example Example Control 17A 17B TreatmentNone 5% CMC 10% Isostearic Acid 5% pH 9.48 9.51 9.72 OdorNeutralization, μl/g) 1851 877 738

EXAMPLE 18

In this example a magnesium zinc silicate (MgZnSiO₄) was prepared,treated with different organic films and then tested for odorneutralization. The zinc sulfate reactant was prepared by mixing 287.54g ZnSO₄.7H₂O and 700 g water and then heating the mixture to 60° C. withmixing to dissolve the zinc sulfate. The sodium silicate reactant wasprepared by diluting 1280 g of a 3.3 mole ratio sodium silicate solution(waterglass) at 21% solids with 741 g water to a final concentration of13.3%. Zinc silicate was formed by adding the zinc sulfate reactant tothe sodium silicate solution formed above at a rate of 29 ml/min for 30minutes. The mixture was then digested for 15 minutes. The resultingzinc silicate was recovered by filtration, reslurried in hot water,refiltered, and washed with hot water. To form the magnesium zincsilicate, 1365 g of the zinc silicate filter cake (20.3% solids)previously prepared was slurried with 300 g water and then 272 g Mg(OH)₂solution at 51% solids was added. The mixture was heated to 90° C. anddigested for 1 hour. The resulting magnesium zinc silicate was thenfiltered and the filter cake (wet cake) was retained for furthercoating. A portion of the filter cake was dried overnight at 150° C.,milled and designated as Example 18 Control. Example 18 Control had anoil absorption of 72 ml/100 g and a BET surface area of 23 M²/g.

The formed magnesium zinc silicate was next coated with various organicfilms and evaluated for odor neutralization. The coating was prepared bycombining 158.7 g of the magnesium zinc silicate filter cake (31.5%solids) prepared above, 391.3 g water and 250 g of a 1% CEKOL® 2000 CMCsolution. The mixture was heated to 95° C. and digested for 1 hour. TheCMC coated magnesium zinc silicate was recovered by filtration and driedovernight at 105° C. and is designated as Example 18A.

The formed magnesium zinc silicate was next coated with isostearic acidby combining 57.1 g of the calcium magnesium silicate wet cake (31.5%solids) prepared above and 2.0 g isostearic acid and mixing until themixture began a homogenous fluid. The mixture was then dried overnightat 105° C. and the dried isostearic acid coated magnesium zinc silicateis designated as Example 18B. Several properties of Example 18 Control,Example 18A and Example 18B were measured according to the methodsdescribed above and are summarized below in Table 14. TABLE 14 SampleExample 18 Example Example Control 18A 18B Treatment None 5% CMC 10%Isostearic Acid 5% pH 9.33 9.51 — Odor Neutralization, μl/g) 1419 1107911

1. A particulate amorphous metal silicate material that is at leastpartially coated with an organic film, wherein said organic film iscomprised of at least one hydrophobic material, wherein said hydrophobicmaterial is selected from the group consisting of polyvinyl acetate,water-insoluble polyacrylamide, polyvinyl chloride, polystyrene,polyethylene, polymethacrylate, paraffin wax, carnauba wax, beeswax,stearyl alcohol, zein, shellac, edible fat, fatty acids, alkali metalsalts of fatty acids, and any combinations thereof; and wherein saidorganic film exhibits either a) an ability to erode when subjected tosufficient pH changes or b) sufficient porosity to permit migration ofmetal ions or isovaleric acid therethrough.
 2. The material of claim 1wherein said metal silicate material is represented by the formulaCa_(x)M_(y)SiO_(z), wherein M is one or more multivalent cationsselected from Mg, Al, and Zn, and x is the number of moles of thecalcium cations and is between 0 and 4, y is the number of moles of suchother metal cations and is between 0 and 4, z is the number of molesrequired to balance the overall charge of the metal cations, and x+y isfrom 1 to
 6. 3. The material of claim 2 wherein said metal silicatematerial is selected from the group consisting of calcium silicate,calcium magnesium silicate, calcium zinc silicate, magnesium silicate,magnesium zinc silicate, and calcium aluminosilicate.
 4. The material ofclaim 3 wherein said metal silicate material is calcium silicate.
 5. Apersonal care composition comprising i) at least one compound selectedfrom the group consisting of a dermatologically acceptable vehicle andan antiperspirant salt, and a combination of both, and ii) at least onematerial as defined in claim
 1. 6. The personal care composition ofclaim 5 and wherein said at least one compound is a dermatologicallyacceptable vehicle selected from the group consisting of an aqueousvehicle, a non-aqueous vehicle, or a combination of both.
 7. Thepersonal care composition of claim 6 wherein said vehicle is selectedfrom the group consisting of water, at least one water-miscible organicliquid, at least one dispersible organic liquid, at least onewater-immiscible liquid, at least one wax, and any combinations thereof.8. A personal care composition comprising at least one compound selectedfrom the group consisting of a dermatologically acceptable vehicle andan antiperspirant salt, and a combination of both, and at least onematerial as defined in claim
 2. 9. The personal care composition ofclaim 8 and wherein said at least one compound is a dermatologicallyacceptable vehicle selected from the group consisting of an aqueousvehicle, a non-aqueous vehicle, or a combination of both.
 10. Thepersonal care composition of claim 9 wherein said vehicle is selectedfrom the group consisting of water, at least one water-miscible organicliquid, at least one dispersible organic liquid, at least onewater-immiscible liquid, at least one wax, and any combinations thereof.11. A personal care composition comprising at least one compoundselected from the group consisting of a dermatologically acceptablevehicle and an antiperspirant salt, and a combination of both, and atleast one material as defined in claim
 3. 12. The personal carecomposition of claim 11 and wherein said at least one compound is adermatologically acceptable vehicle selected from the group consistingof an aqueous vehicle, a non-aqueous vehicle, or a combination of both.13. The personal care composition of claim 12 wherein said vehicle isselected from the group consisting of water, at least one water-miscibleorganic liquid, at least one dispersible organic liquid, at least onewater-immiscible liquid, at least one wax, and any combinations thereof.14. The personal care composition of claim 5 wherein said compound is anantiperspirant salt selected from the group consisting of aluminumhalides, aluminum hydroxy-halides, zirconyl oxyhalides, zirconylhydroxy-halides, and any mixtures thereof.
 15. The personal carecomposition of claim 14 wherein said antiperspirant salt is selectedfrom the group consisting of aluminum chloride; aluminum hydroxyhalidescorresponding with the formula Al₂(OH)_(x)Q_(y)XH₂O where Q is chlorine,bromine or iodine, wherein x is from about 2 to about 5, and x+y=about6, and x and y do not need to be integers, and where X is from about 1to about 6; zirconium oxy salts; zirconium hydroxy salts represented bythe general empirical formula:ZrO(OH)₂-n_(z)B_(z) wherein z may vary from about 0.9 to about 2 andneed not be an integer, n is the valence of B, 2-nz is greater than orequal to 0, and B may be selected from the group consisting of halides,nitrate, sulfamate, sulfate; and any mixtures thereof.
 16. The personalcare composition of claim 8 wherein component ii) is an antiperspirantsalt selected from the group consisting of aluminum halides, aluminumhydroxy-halides, zirconyl oxyhalides, zirconyl hydroxy-halides, and anymixtures thereof.
 17. The personal care composition of claim 16 whereinsaid antiperspirant salt is selected from the group consisting ofaluminum chloride; aluminum hydroxyhalides corresponding with theformula Al₂(OH)_(x)Q_(y)XH₂O where Q is chlorine, bromine or iodine,wherein x is from about 2 to about 5, and x+y=about 6, and x and y donot need to be integers, and where X is from about 1 to about 6;zirconium oxy salts; zirconium hydroxy salts represented by the generalempirical formula:ZrO(OH)₂-n_(z)B_(z) wherein z may vary from about 0.9 to about 2 andneed not be an integer, n is the valence of B, 2-nz is greater than orequal to 0, and B may be selected from the group consisting of halides,nitrate, sulfamate, sulfate; and any mixtures thereof.
 18. A method ofinhibiting body odor by applying to a person's skin an effective amountof the personal care composition of claim
 14. 19. A method of inhibitingbody odor by applying to a person's skin an effective amount of thepersonal care composition of claim 16.